North Dakota Rep. Kevin Cramer is taking to the airwaves to combat Democratic ads that spotlight the Republican Senate candidate’s health care positions.

The new Cramer ad features images of three Democratic spots — two of them from outside Democratic groups and one from Democratic incumbent Heidi Hetikamp’s campaign. Cramer has been calling on Heitkamp to take down her own campaign’s ad, saying she is citing inaccurate information about how his health care votes would have affected people with pre-existing conditions.

“Heidi, stop trying to mislead North Dakota,” the narrator says in the 30-second spot shared first with Roll Call. The ad is part of a six-figure buy and will run on broadcast and cable networks and online.

“Here’s the truth: Kevin Cramer voted for guaranteed coverage for pre-existing conditions, and Heidi’s ads attacking Kevin on health care don’t pass the smell test,” the narrator says, followed by a cow mooing. (The mooing cow has appeared in other Cramer ads to portray outside Democratic ads leveling false attacks, or giving voters a “bum steer.”)

Watch: ‘North Dakota Nice’ Takes a Backseat in Senate Race

The claims in both candidates’ health care ads are muddled in details that don’t fit into a 30-second spot, which fact-checking outlets have examined.

Cramer’s latest ad says he voted for “guaranteed coverage” for people with pre-existing conditions and cites his vote for the GOP bill known as the American Health Care Act, which would have repealed much of the 2010 health care law.

Nonpartisan fact-checking website Politifact found that the GOP bill did maintain the health care law’s requirement that people with pre-existing conditions could not be denied health insurance coverage. However, the bill also eliminated limits on how much people with pre-existing conditions could be charged for their insurance.

Politifact ruled that the claim that the GOP bill “absolutely does not eliminate protections for pre-existing conditions” was “Mostly False,” noting the AHCA would “weaken” protections for people with pre-existing conditions.

Heitkamp’s ad titled “Denise” features a woman with heart disease, who says to the camera, “Mr. Cramer, I don’t know why you voted to let insurance companies go back to denying coverage for pre-existing conditions, but I know Heidi would never do that.”

Politifact noted that just a fraction of the 300,000 with pre-existing conditions in North Dakota would have been affected if the GOP bill became law, because most of them are in group plans and the impact would mainly be in the individual market.

The Associated Press also determined that Heitkamp “overstates” the number of people with pre-existing conditions who would have been denied coverage before the 2010 health care law.

But Politifact also noted that while the bills Cramer voted for required coverage for people with pre-existing conditions, they “watered down” provisions that would have limited coverage costs. According to Politifact, the bills to repeal the 2010 law “would have sent premiums skyrocketing, experts say, to the point that coverage for many would be unattainable.”

Heitkamp and other Democratic candidates across the country have been making health care a top issue in their campaigns. A source close to Cramer’s campaign denied that his team is spending resources responding to the Democratic health care ads because they saw shifting poll numbers. The source said Cramer’s team just wanted to set the record straight. (His campaign has aired other 30-second spots responding to ads from the Senate Majority PAC, which is aligned with Senate Democratic leadership.)